TVMediaHub/TVMediaHub.Tizen/Extensions/DropdownListRenderer.cs

   1 using ElmSharp;
   2 using System;
   3 using System.Collections;
   4 using System.Collections.Generic;
   5 using System.Collections.Specialized;
   6 using System.ComponentModel;
   7 using Tizen.Xamarin.Forms.Extension;
   8 using Tizen.Xamarin.Forms.Extension.Renderer;
   9 using Xamarin.Forms;
  10 using Xamarin.Forms.Platform.Tizen;
  11 using TForms = Xamarin.Forms.Platform.Tizen.Forms;
  12
  13 [assembly: ExportRenderer(typeof(DropdownList), typeof(DropdownListRenderer))]
  14
  15 namespace Tizen.Xamarin.Forms.Extension.Renderer
  16 {
  17     public class DropdownListRenderer : ViewRenderer<DropdownList, Hoversel>
  18     {
  19         class DropdownItem : BindableObject
  20         {
  21             public static readonly BindableProperty TextProperty = BindableProperty.Create("Text", typeof(string), typeof(DropdownItem), default(string));
  22
  23             public string Text
  24             {
  25                 get { return (string)GetValue(TextProperty); }
  26                 set { SetValue(TextProperty, value); }
  27             }
  28
  29             public HoverselItem HoverselItem { get; set; }
  30             public object Data { get; set; }
  31         }
  32
  33         Dictionary<HoverselItem, DropdownItem> _items = new Dictionary<HoverselItem, DropdownItem>();
  34         Dictionary<object, DropdownItem> _objectMap = new Dictionary<object, DropdownItem>();
  35         object _selectedItem = null;
  36
  37         protected override void OnElementChanged(ElementChangedEventArgs<DropdownList> e)
  38         {
  39             if (Control == null)
  40             {
  41                 var dropdownList = new Hoversel((TForms.Context as FormsApplication).MainWindow);
  42                 SetNativeControl(dropdownList);
  43                 Control.ItemSelected += OnHoverselItemSelected;
  44                 Control.Dismissed += OnDismissed;
  45                 Control.Expanded += OnExpanded;
  46             }
  47             if (e.OldElement != null)
  48             {
  49                 e.OldElement.ExpandChangeRequested -= OnExpandChangeRequested;
  50                 e.OldElement.CollectionChanged -= OnCollectionChanged;
  51                 ClearItems();
  52             }
  53             if (e.NewElement != null)
  54             {
  55                 e.NewElement.ExpandChangeRequested += OnExpandChangeRequested;
  56                 e.NewElement.CollectionChanged += OnCollectionChanged;
  57                 Control.HoverParent = (TForms.Context as FormsApplication).MainWindow;
  58
  59                 AddItems(e.NewElement.ItemsSource);
  60                 UpdateIsExpanded();
  61                 UpdateSelectedItem();
  62             }
  63             base.OnElementChanged(e);
  64         }
  65
  66         void OnHoverselItemSelected(object sender, HoverselItemEventArgs e)
  67         {
  68             Element.SelectedItem = GetItem(e.Item)?.Data;
  69         }
  70
  71         void OnExpanded(object sender, EventArgs e)
  72         {
  73             Element?.SetValue(DropdownList.IsExpandedPropertyKey, true);
  74         }
  75
  76         void OnDismissed(object sender, EventArgs e)
  77         {
  78             Element?.SetValue(DropdownList.IsExpandedPropertyKey, false);
  79         }
  80
  81         protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
  82         {
  83             if (e.PropertyName == DropdownList.IsExpandedProperty.PropertyName)
  84             {
  85                 UpdateIsExpanded();
  86             }
  87             else if (e.PropertyName == DropdownList.DisplayMemberPathProperty.PropertyName)
  88             {
  89                 UpdateDisplayMemberPath();
  90             }
  91             else if (e.PropertyName == DropdownList.SelectedItemProperty.PropertyName)
  92             {
  93                 UpdateSelectedItem();
  94             }
  95             else if (e.PropertyName == DropdownList.ItemsSourceProperty.PropertyName)
  96             {
  97                 UpdateItemSource();
  98             }
  99             base.OnElementPropertyChanged(sender, e);
 100         }
 101
 102         void UpdateItemSource()
 103         {
 104             ClearItems();
 105             AddItems(Element.ItemsSource);
 106         }
 107
 108         void UpdateIsExpanded()
 109         {
 110             if (Element.IsExpanded)
 111             {
 112                 Control.HoverBegin();
 113             }
 114             else
 115             {
 116                 Control.HoverEnd();
 117             }
 118         }
 119
 120         void UpdateSelectedItem()
 121         {
 122             _selectedItem = Element.SelectedItem;
 123             DropdownItem item = GetItem(Element.SelectedItem);
 124             if (item == null)
 125             {
 126                 Element.SelectedItem = null;
 127                 Control.Text = string.Empty;
 128             }
 129             else
 130             {
 131                 Control.Text = item.Text;
 132             }
 133         }
 134
 135         void OnExpandChangeRequested(object sender, DropdownList.ExpandRequestArgs e)
 136         {
 137             if (e.IsExpand)
 138             {
 139                 Control.HoverBegin();
 140             }
 141             else
 142             {
 143                 Control.HoverEnd();
 144             }
 145         }
 146
 147         void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
 148         {
 149             if (e.NewItems != null)
 150             {
 151                 AddItems(e.NewItems);
 152             }
 153             if (e.OldItems != null)
 154             {
 155                 RemoveItems(e.OldItems);
 156             }
 157             if (e.Action == NotifyCollectionChangedAction.Reset)
 158             {
 159                 ClearItems();
 160             }
 161         }
 162
 163         void AddItems(IEnumerable items)
 164         {
 165             foreach (object item in items)
 166             {
 167                 DropdownItem dropdownItem = new DropdownItem()
 168                 {
 169                     Data = item,
 170                 };
 171                 if (!string.IsNullOrEmpty(Element.DisplayMemberPath))
 172                 {
 173                     dropdownItem.SetBinding(DropdownItem.TextProperty, new Binding(Element.DisplayMemberPath));
 174                 }
 175                 else
 176                 {
 177                     dropdownItem.Text = item.ToString();
 178                 }
 179                 dropdownItem.BindingContext = item;
 180                 dropdownItem.HoverselItem = Control.AddItem(dropdownItem.Text);
 181                 dropdownItem.PropertyChanged += OnDropdownItemTextChanged;
 182                 _items[dropdownItem.HoverselItem] = dropdownItem;
 183                 _objectMap[item] = dropdownItem;
 184             }
 185         }
 186
 187         void OnDropdownItemTextChanged(object sender, PropertyChangedEventArgs e)
 188         {
 189             if (e.PropertyName == DropdownItem.TextProperty.PropertyName)
 190             {
 191                 DropdownItem item = (DropdownItem)sender;
 192                 item.HoverselItem?.SetPartText("default", item.Text);
 193                 if (_selectedItem == item.Data)
 194                 {
 195                     Control.Text = item.Text;
 196                 }
 197             }
 198         }
 199
 200         void UpdateDisplayMemberPath()
 201         {
 202             foreach (var item in _items.Values)
 203             {
 204                 if (!string.IsNullOrEmpty(Element.DisplayMemberPath))
 205                 {
 206                     item.SetBinding(DropdownItem.TextProperty, new Binding(Element.DisplayMemberPath));
 207                 }
 208                 else
 209                 {
 210                     item.Text = item.Data.ToString();
 211                 }
 212             }
 213             UpdateSelectedItem();
 214         }
 215
 216         void RemoveItems(IEnumerable items)
 217         {
 218             foreach (object item in items)
 219             {
 220                 var dropdownItem = GetItem(item);
 221                 if (Element.SelectedItem == dropdownItem.Data)
 222                 {
 223                     Element.SelectedItem = null;
 224                 }
 225                 dropdownItem.PropertyChanged -= OnDropdownItemTextChanged;
 226                 _items.Remove(dropdownItem.HoverselItem);
 227                 _objectMap.Remove(item);
 228                 dropdownItem.HoverselItem.Delete();
 229             }
 230         }
 231
 232         void ClearItems()
 233         {
 234             Control.Clear();
 235             _items.Clear();
 236             _objectMap.Clear();
 237
 238             Element.SelectedItem = null;
 239         }
 240
 241         DropdownItem GetItem(object obj)
 242         {
 243             if (obj == null)
 244                 return null;
 245             DropdownItem item = null;
 246             _objectMap.TryGetValue(obj, out item);
 247             return item;
 248         }
 249
 250         DropdownItem GetItem(HoverselItem selItem)
 251         {
 252             if (selItem == null)
 253                 return null;
 254             DropdownItem item = null;
 255             _items.TryGetValue(selItem, out item);
 256             return item;
 257         }
 258     }
 259 }